TWI417309B - Aqueous radiation curable polyurethane compositions - Google Patents

Description

Aqueous radiation hardening type polyurethane composition

The present invention relates to an aqueous radiation-curable polyurethane composition which is particularly suitable for the manufacture of highly scratch resistant coatings.

It has long been known that radiation hardening polyurethane dispersions provide coatings on different substrates such as wood, plastic and metal, which exhibit good mechanical and chemical resistance and some flexibility.

Ethylene-unsaturated polyurethane has been produced by extending a chain of isocyanate-terminated ethylene-unsaturated polyurethane prepolymers with a polyamine. The resulting polymer usually has a high molecular weight and contains a hard urea fraction, which usually results in a dispersion having a minimum film formation temperature, and thus requires the use of an agglomeration aid. Ethylene-unsaturated polyurethanes can also be prepared by capping an isocyanate-terminated polyurethane prepolymer with an ethylenically unsaturated (particularly (meth) acrylated) monomer.

The disadvantages of these known radiation hardening compositions are that they provide a high reactivity limit that makes them less suitable for applications requiring high speed or low energy hardening. It is also less suitable for the manufacture of colored coatings in which pigments are present to reduce UV light penetration and to limit overall good hardening. These compositions generally do not provide coatings with high end hardness, scratch resistance and stain resistance.

A radiation hardenable polyurethane dispersion having overcome these problems has been discovered.

The invention therefore relates to an aqueous radiation-curable composition comprising - at least one (meth)acrylated polyurethane prepolymer (A) obtained from at least one polyisocyanate (i), optionally At least one polyol (ii), at least one containing at least one reactive group reactive with an isocyanate group, and allowing the polyurethane prepolymer to be dispersed directly or after reacting with a neutralizing agent to provide a salt a hydrophilic compound (iii) in an aqueous medium, at least one (meth)acrylic compound (iv) containing at least two reactive groups reactive with an isocyanate group, at least one of which is substantially compatible with isocyanic acid a reaction of a reactive group of a (meth)acrylic compound (v); and - optionally, at least one ethylenically unsaturated compound (B), wherein the composition comprises (i), (ii), (iii) And (iv), (v), and (B), the total weight is at least 3 meq (meth) acrylated and optionally polymerizable ethylenically unsaturated groups.

The polymerizable ethylenically unsaturated group is used in the present invention to represent a carbon-carbon double bond which is capable of undergoing free radical polymerization under the influence of an irradiation and/or a (photo) initiator. The polymerizable ethylenically unsaturated group is usually selected from (meth)acrylic acid and allyl group, preferably (meth)acrylic group, and most preferably an acrylic group. It should be understood in the present invention that the term "(meth)acrylic group" includes acrylic acid and methacrylic compounds or derivatives and mixtures thereof.

The composition according to the invention is characterized by a high content of (meth)acrylated and optionally polymerizable ethylenically unsaturated groups; which comprise (i), (ii), (iii), (iv), (v) And (B) the total weight in grams is at least 3 meq (meth) acrylated, optionally polymerizable ethylenically unsaturated groups.

The amount of (meth)acrylated ethylenically unsaturated groups is typically measured by nuclear magnetic resonance spectroscopy and is expressed in meq per gram of solid state material. A sample of the composition was dried at room temperature for 1 day and at 60 ° C for 12 hours, and then dissolved in N-methylpyrrolidone. The sample was subjected to 1 H-NMR analysis using 1,3,5-bromobenzene as an internal standard to measure the molar concentration of the (meth)acrylated ethylenically unsaturated group. According to the formula (A×B)/C, where A is the integral value of the 1H double bond provided by the sample, B is the molar number of the internal standard in the sample, and C is the integral value of 1H provided by the internal standard, and the comparison is specified. The molar concentration of the (meth)acrylated ethylenically unsaturated group can be calculated as the peak of the aromatic proton of the internal standard and the peak designated as the (meth)acrylated ethylenic unsaturated double bond.

Alternatively, the amount of the (meth) acrylated ethylenically unsaturated group may be measured by titration by adding an excess of dibromosulfate sulfate (in glacial acetic acid as a solvent and mercury acetate as a catalyst) to the unsaturated group. The excess free bromide ions are then titrated with sodium thiosulfate in the presence of potassium iodate and iodine.

Preferably, the total amount of (meth)acrylated and polymerizable ethylenically unsaturated groups is based on the total weight of the compounds (i), (ii), (iii), (iv), (v), and (B). The (meth)acrylated polymerizable ethylenically unsaturated group is considered to be at least 3.5 meq, in particular at least 4 meq.

Preferably, the total amount of (meth)acrylated and polymerizable ethylenically unsaturated groups is based on the total weight of the compounds (i), (ii), (iii), (iv), (v), and (B). A (meth)acrylated polymerizable ethylenically unsaturated group of not more than 10 meq.

The radiation hardening type composition is preferably obtained by a method comprising the following steps: - a first step comprising reacting compounds (i), (iii) and (iv), optionally, and compound (ii), - a second step, The product comprising the first step of the reaction and the compound (v) are such that a blocked (meth)acrylated polyurethane prepolymer is obtained; the blocked (meth) acrylate obtained after the second step The polyurethane prepolymer is dispersed in an aqueous medium, optionally, comprising reacting with a neutralizing agent to convert the hydrophilic group provided by the compound (iii) into an anionic salt, - a step of selecting a chain extender (vii) a (meth)acrylated polyurethane prepolymer obtained after the second step, optionally adding an ethylenically unsaturated compound (B).

The method may be carried out by reacting a stoichiometric excess of the compound (i) with the compounds (ii), (iii) and (iv), preferably under substantially anhydrous conditions and between 30 ° C and 130 ° C, more preferably 70 The temperature between ° C and 100 ° C is carried out until the reaction between the isocyanate group and the isocyanate-reactive group is substantially completed. The isocyanate group content can be obtained by titration with an amine. The reactants are usually in an equivalent ratio of the isocyanate group provided by the corresponding compound (i) to the isocyanate-reactive groups provided by the compounds (ii), (iii) and (iv) of from about 1.1:1 to about 2:1. It is preferably used in a ratio of about 1.4:1 to 1.8:1. The reaction can be advantageously carried out by adding 5 to 40, preferably 15 to 25% by weight of a solvent to lower the viscosity of the prepolymer. The solvent is preferably acetone or methyl ethyl ketone. During this process, it is often the use of a catalyst to accelerate the reaction of the isocyanato group to a hydroxyl group, and the use of an inhibitor to prevent reactive unsaturated free radical reactions. A sequential method may be used in the framework of the present invention, wherein compound (i) and/or compounds (ii), (iii) and/or (iv) are added in two or more increments, or continuously fed . It has better control over the exotherm of the reaction, especially in the absence of solvent.

The compounds (ii), (iii) and (iv) are preferably in a molar ratio of 1:1:1 to 1:10:10, more preferably 1:1:1 to 1:5:5 (ii): (iii): (iv) use.

The isocyanate-terminated polyurethane prepolymer is reacted with compound (v) in a subsequent step, preferably under the same conditions as in the previous step. The reactant is usually present in an equivalent ratio of the isocyanate-reactive group provided for the compound (v) to the isocyanate group provided in the first step to about 2:1 to 1:1, preferably about 1.7: Use from 1 to 1.25:1. The isocyanate group content can be obtained by titration with an amine.

The prepolymer obtained after the reaction of (i), (ii), (iii), (iv), and (v) is usually added to the prepolymer by slowly adding the prepolymer to water or vice versa. And dispersed in an aqueous medium. This dispersion is usually carried out under high shear mixing. Dispersion usually requires neutralization of a hydrophilic group (such as a carboxylic acid or a sulfonic acid group) provided by the compound (iii) into an anionic salt. It is usually accomplished by adding an organic or inorganic neutralizing agent to the prepolymer or water. Suitable neutralizing agents include ammonia, volatile organic tertiary amines such as trimethylamine, triethylamine, triisopropylamine, tributylamine, N,N-dimethylcyclohexylamine, N,N-dimethylaniline , N-methylmorpholine, N-methylperazine , N-methylpyrrolidine, and N-methylpiperidine, and non-volatile inorganic bases, including monovalent metal cations, preferably alkali metals such as lithium, sodium and potassium, and anions such as hydroxides, Hydrides, carbonates, and bicarbonates. It is preferably triethylamine and sodium hydroxide.

The total amount of these neutralizing agents can be calculated based on the total amount of acid groups to be neutralized. It typically uses a stoichiometric ratio of about 1:1.

The relative amounts of the compounds (i), (ii), (iii), (iv), and (v) are such that the compound (i) is used for the compounds (ii), (iii), (iv), and (v). A portion of the isocyanate-functional (meth)acrylated polyurethane prepolymer (i.e., a prepolymer that still contains some residual isocyanate groups) is stoichiometrically obtained. This isocyanate functional prepolymer partial chain can then be extended in the aqueous phase with an active hydrogen chain extender, typically at a temperature of from 5 to 90 ° C, preferably from 15 to 30 ° C. Water can be used as a chain extender. It is optionally added to the compound (vii) which comprises an active amine group which can extend the residual isocyanate end group of the prepolymer.

The chain extender is suitably a water-soluble aliphatic, alicyclic, aromatic, or heterocyclic primary or secondary polyamine or hydrazine having up to 60, preferably up to 12, carbon atoms. The total amount of the compound (vii) used is usually calculated in accordance with the amount of residual isocyanate groups present in the polyurethane prepolymer. The ratio of the isocyanato group to the amine group in the chain extender (vii) in the prepolymer during chain extension is usually from about 1:0.7 to about 1:1, preferably from about 1:0.9 to about 1, in terms of equivalents. The ratio of 1:1. In order to obtain a fully reacted polyurethane polymer having no residual free isocyanate groups, the ratio is more preferably 1:1.

The polyamine used preferably has an average of 2 to 4, more preferably 2 to 3, functional groups. Examples of the chain extender (vii) which can be used herein include anthracene, ethylenediamine, piperidine, 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1, 10-decanediamine, 1,12-dodecadiamine, 2-methylpentanediamine, triamethylenetriamine, isophoronediamine (or 1-amino-3-aminomethyl- 3,5,5-trimethylcyclohexane), anthracene (4-aminocyclohexyl)methane, anthracene (4-amino-3-methylcyclohexyl)methane, polyethylenediamine, polyoxyethylene Amines, with polyoxypropylenediamines (such as Jeffamines from TEXACO), and mixtures thereof.

It is preferred not to use the chain extender compound (vii).

The polymer dispersion is usually stripped after forming a dispersion of the prepolymer and when it contains a volatile solvent having a boiling point of less than 100 °C. It is usually carried out at a low pressure and at a temperature between 20 and 90 ° C, preferably between 40 and 60 ° C.

The polyisocyanate compound (i) is used to denote an organic compound comprising at least two isocyanate groups. The polyisocyanate compound typically comprises no more than 3 isocyanato groups. The polyisocyanate compound (i) is preferably diisocyanate.

The polyisocyanate compound is typically selected from the group consisting of aliphatic, cycloaliphatic, aromatic and/or heterocyclic polyisocyanates or combinations thereof.

Examples of aliphatic and cycloaliphatic polyisocyanates are 1,6-diisocyanatohexane (HDI), 1,1'-methylene fluorene [4-isocyanatocyclohexane] (H12MDI), 5-Isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane (isophorone diisocyanate, IPDI). The aliphatic polyisocyanate containing more than 2 isocyanato groups is, for example, a derivative of the above diisocyanate such as 1,6-diisocyanatohexanediurea and an isomeric cyanurate.

Examples of aromatic polyisocyanates are 1,4-diisocyanatobenzene (BDI), 2,4-diisocyanatotoluene (TDI), 1,1'-methylene hydrazine [4-isocyanate Benzene] (MDI), xylene diisocyanate (XDI), tetramethyl xylene diisocyanate (TMXDI), 1,5-naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), and benzoic acid Diisocyanate (PPDI).

The polyisocyanate is preferably selected from the group consisting of aliphatic and cycloaliphatic polyisocyanates, more preferably diisocyanate. It is particularly preferably 1,1'-methylene hydrazine [4-isocyanatocyclohexane].

The polyisocyanate compound (i) used for the synthesis of the polyurethane prepolymer (A) is usually used in an amount of 10 to 60% by weight, preferably 20% by weight of the polyurethane prepolymer (A). It is up to 50% by weight, and more preferably in the range of 30 to 40% by weight.

The polyol (ii) is used to represent a polyol comprising at least two hydroxyl groups. The polyol (ii) may be selected from high molecular weight polyols having a number average molecular weight of at least 400, low molecular weight polyols having a number average molecular weight of less than 400, or any mixture thereof. The high molecular weight polyol (ii) preferably has a number average molecular weight of not more than 5,000, preferably not more than 2,000, more preferably not more than 1,000.

Examples of such high molecular weight polyols are polyester polyols, polyether polyols, polycarbonate polyols, fat dimer diols, polybutadiene polyols, polyoxyl polyols, and polyacrylate polyols. And their combinations.

Suitable polyether polyols include polyethylene glycol, polypropylene glycol and polytetramethylene glycol, or block copolymers thereof.

Suitable polycarbonate polyols include diols such as ethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- Hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, or tetraethylene glycol) with phosgene, with dialkyl carbonate (such as dimethyl carbonate), with diaryl carbonate (such as Diphenyl carbonate), or a reaction product with a cyclic carbonate such as ethyl carbonate and/or propyl ester.

Suitable fatty dimer diols are obtained by hydrogenation of a dimer acid, which preferably comprises 36 carbon atoms.

Suitable polyacrylate polyols include free radical polymerization initiated by a thermal free radical initiator in the presence of a hydroxylated mercaptan by means of a (meth)acrylic acid and/or a (meth)acrylamide monomer, followed by a short chain diol (e.g., 1,4-butanediol) is prepared by transesterification of a terminal group.

It is preferably a polyester, a polyether and a polycarbonate polyol.

It is particularly preferably a polyester polyol, especially a hydroxyl terminated reaction product of a polyhydroxy (preferably dihydroxy) alcohol with a polycarboxylic acid (preferably a dicarboxylic acid) or its corresponding anhydride, and opened by a lactone. The ring polymerization is obtained. The polycarboxylic acids which can be used to form these polyester polyols can be aliphatic, cycloaliphatic, aromatic and/or heterocyclic, and they can be substituted, saturated or unsaturated. Examples of dicarboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, hexahydrononanoic acid, isodecanoic acid, p-nonanoic acid, ortho Citrate, tetrachlorodecanoic acid, 1,5-naphthalene dicarboxylic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid, tetrahydrofurfuric acid, 1,2, 4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, with pyromic acid, or a mixture thereof. The polyester polyols may also contain air-dried ingredients such as long-chain unsaturated aliphatic acids, especially fatty acid dimers.

Preferred polyhydric alcohols for the preparation of polyester polyols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, dibutyl glycol, 2-methyl-1,3-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, biphenol A or hydrogenated biphenol A ethylene oxide adduct or propylene oxide addition Things. Polyols such as glycerin, trimethylolethane, trimethylolpropane, di-trimethylolethane, di-trimethylolpropane, and pentaerythritol may also be used.

It is particularly preferably a polyester polyol produced by the condensation of neopentyl glycol with adipic acid and/or isophthalic acid.

The total amount of the polyol (ii) in the polyurethane prepolymer (A) is preferably from 2 to 50% by weight, more preferably from 3 to 30% by weight based on the polyurethane prepolymer (A). %, preferably from 5 to 15% by weight.

Examples of low molecular weight polyols are ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1, 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 2-ethyl -1,6-hexanediol, cyclohexanedimethanol, trimethylolpropane, di-trimethylolpropane, glycerol, pentaerythritol, and diisopentaerythritol.

According to a specific embodiment of the invention, a high molecular weight polyol is used in the preparation of the prepolymer (A).

According to another specified embodiment of the invention, a mixture of a high molecular weight polyol and a low molecular weight polyol is used.

The hydrophilic compound (iii) is usually a polyol including a functional group which can exhibit an ionic or nonionic hydrophilic nature. It is preferably a polyol containing one or more anionic salt groups such as a carboxylic acid and a sulfonate group or an acid group which can be converted into an anionic salt group such as a carboxylic acid or a sulfonic acid group. It is preferably a hydroxycarboxylic acid represented by the formula (HO) _x R(COOH) _y wherein R represents a linear or branched hydrocarbon residue having 1 to 12 carbon atoms, and x and y are independently 1 An integer of up to 3. Examples of such hydroxycarboxylic acids include citric acid, oxysuccinic acid, lactic acid, and tartaric acid. The most preferred hydroxycarboxylic acid is α,α-dimethylol alkanoic acid, such as 2,2-dimethylolpropionic acid and 2,2-dimethylol, of which x=2 and y=1 in the above formula. Butyric acid.

The amount of the hydrophilic compound (iii) is usually from 1 to 25% by weight, preferably from 4 to 10% by weight, based on the prepolymer (A) of the polyurethane.

The (meth)acrylic compound (iv) containing at least two reactive groups reactive with an isocyanate group and at least one (meth)acrylic group is used in the present invention to represent a type comprising at least one (meth)acrylic acid. a compound having a functional group (such as acrylic acid or methacrylic acid group) and at least two nucleophilic functional groups (preferably hydroxy functional groups) reactive with an isocyano group.

It is preferably a (meth) propylene fluorenyl dihydroxy compound and a poly(meth) propylene fluorenyl dihydroxy compound.

It is preferably a compound (iv) comprising two hydroxy functional groups and at least two (meth)acrylic groups. Particularly good for acrylic acid.

Particularly preferred compound (iv) is obtained by reacting a diepoxypropyl compound with (meth)acrylic acid.

It may use an aliphatic bicyclic ring derived from a polyoxyalkylene glycol having 4 to 12 carbon atoms or an oxygen-containing alkylene group (particularly polyethylene glycol, polypropylene glycol or a mixture thereof). Oxypropyl propyl compound. For example, it prefers 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, polyethylene glycol diglycidyl ether, Polypropylene glycol diglycidyl ether, hydrogenated phenol A diglycidyl ether, hydrogenated biphenol F diglycidyl ether, and its oxidative and / or propoxylated. It is also possible to use a diglycidyl ester such as diglycidyl hexahydrophthalate. It is preferably an aromatic diepoxypropyl compound derived from biphenol A and biphenol F. Particularly preferred are bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and ethoxylated and/or propoxylated. It is also possible to use diglycidyl esters such as diglycidyl decanoate, N,N-diepoxypropylaniline, N,N-diepoxypropyl-4-glycidoxyaniline. Particularly preferred is a diacrylate of bisphenol A diglycidyl ether.

It is also possible to use a compound (iv) obtained by esterifying a portion of an aliphatic or aromatic polyhydric polyol with (meth)acrylic acid having a residual average hydroxy functional group in the molecule of at least 2.0. In this connection, it is also possible to use the reaction product of this polyol with ethylene oxide and/or propylene oxide or a mixture thereof, or the reaction product of this polyol with a lactone, which is added to the ring-opening reaction. Examples of suitable lactones are γ-butyrolactone, in particular δ-valerolactone and ε-caprolactone. It is preferably an alkoxylated polyol having no more than 2 alkoxy groups per hydroxy functional group, and a modified polyol via ε-caprolactone. It is known to those skilled in the art to carry out (meth)acrylation of a polyol such as glycerol, trimethylolpropane, isoamyltetraol, di-trimethylolpropane or di-isoprene. A mixture of two, three, four, five, and six (meth) acrylates, and one possible means of characterizing the mixture is the measurement of its hydroxyl number. Examples are glycerol mono(meth)acrylate, trimethylolpropane mono(meth)acrylate, pentaerythritol di(meth)acrylate, di-trimethylolpropane di(meth)acrylate , diisopentaerythritol tetra (meth) acrylate, and its polyethoxylate and / or polypropoxy oxidation.

Hydrolyzed compounds (iv) derived from aliphatic, cycloaliphatic or aromatic compounds having an epoxy functional group and at least one (meth)acrylic functional group can also be used. It is particularly suitable as a product obtained by hydrolysis of glycidyl (meth)acrylate (i.e., 1,2-dihydroxy-3-(methyl)propenylpropane).

The amount of the compound (iv) is usually from 5 to 30% by weight, preferably from 10 to 20% by weight, based on the prepolymer (A) of the polyurethane.

The (meth)acrylic compound (v) containing a reactive group reactive with an isocyanate group in the present invention is used in the present invention to mean a group comprising at least one unsaturated functional group (such as acrylic acid or methacrylic acid group) and A compound which is reactive with an isocyanate group, preferably a hydroxy group. It is preferably a (meth) propylene fluorenyl monohydroxy compound, more particularly a poly(meth) propylene fluorenyl monohydroxy compound. Particularly preferred is acrylate. Useful compounds (v) include esterified products of aliphatic and/or aromatic polyols with (meth)acrylic acid having a residual average hydroxyl functional group of about 1. It is preferably a partially esterified product of (meth)acrylic acid with a tri, tetra, penta, or hexahydroxy polyol or a mixture thereof. In this connection, it is also possible to use the reaction product of this polyol with ethylene oxide and/or propylene oxide or a mixture thereof, or the reaction product of this polyol with a lactone, which is added to the ring-opening reaction. Examples of suitable lactones are γ-butyrolactone, in particular δ-valerolactone and ε-caprolactone. These modified or unmodified polyols are partially modified with acrylic acid, methacrylic acid or mixtures thereof until the desired residual hydroxyl functional groups are achieved.

Compound (v) obtained by the reaction of (meth)acrylic acid with an aliphatic, cycloaliphatic or aromatic compound having an epoxy functional group and at least one (meth)acrylic functional group can also be used.

Other suitable compounds are (meth) acrylates in which at least one hydroxy functional group is still free of linear or branched polyols, such as hydroxyalkyl (meth) acrylates having from 1 to 20 carbon atoms in the alkyl group. Preferred molecules of this type are hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Particularly preferred are compounds comprising at least two (meth)acrylic functional groups, such as glyceryl diacrylate, trimethylolpropane diacrylate, glycerol diacrylate, pentaerythritol triacrylate, di-trihydroxyl Propane triacrylate, diisopentaerythritol pentaacrylate, and (poly) ethoxylated and / or (poly) propoxylated.

The amount of the compound (v) is usually from 10 to 60% by weight, preferably from 30 to 50% by weight, based on the prepolymer (A) of the polyurethane.

Preferably, the total amount of the (meth) acrylate groups in the prepolymer (A) is at least the total weight of the compounds (i), (ii), (iii), (iv), and (v). 3.0 meq, especially a (meth)acrylated group of at least 3.5 meq.

Preferably, the total amount of (meth) acrylated groups is not more than 10 meq (mole) based on the total weight of the compounds (i), (ii), (iii), (iv), and (v) ) acrylated base.

The composition according to the invention preferably comprises at least one ethylenically unsaturated compound (B) which is a compound comprising at least one unsaturated functional group (such as acrylic acid, methacrylic acid, or allyl), more particularly (Poly) (meth) propylene fluorenyl compound. It is preferably an acrylate.

The ethylenically unsaturated compound (B) may be selected from the above (meth)acrylic compounds (iv) and (v), or may be an ethylenically unsaturated compound excluding a functional group reactive with an isocyanate group.

The compound (B) is preferably an ethylenically unsaturated compound selected from the group consisting of a (meth)acrylic compound (v) and a functional group which does not include an isocyanate group.

Particularly preferred are aliphatic and aromatic polyhydroxy polyols which have been fully esterified with (meth)acrylic acid and which are substantially free of residual hydroxyl functional groups in the molecule. Suitable are esterification products of (meth)acrylic acid with tri-, tetra-, penta- and/or hexahydroxy polyols and mixtures thereof. In this connection, the reaction product of this polyol with ethylene oxide and/or propylene oxide or a mixture thereof, or the reaction product of this polyol with a lactone, which is added to the ring-opening reaction, can be used. Examples of suitable lactones are γ-butyrolactone, in particular δ-valerolactone and ε-caprolactone. It prefers to use an alkoxylated polyol having no more than two alkoxy groups per hydroxy functional group, and modifying the polyol via ε-caprolactone. These modified or unmodified polyols are preferably fully esterified with acrylic acid, methacrylic acid or mixtures thereof until substantially no residual hydroxyl functional groups remain. Examples of such polyunsaturated compounds are trimethylolpropane triacrylate, glycerol triacrylate, pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, di-isopentyltetraol hexaacrylate Esters, their (poly) ethoxylated and/or (poly) propoxylated, and the like. It is also possible to use methacrylate (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, and (meth) acrylate (meth) acrylate or Any compound of the mixture.

Compound (B) can also be an ethylenically unsaturated compound with one or more additional functional groups or side chains that provide additional properties to the polymer. Deuterated and / or fluorinated ethylene unsaturated compounds, such as the trade names IRR 154 and ADDITOL Commercially available products of HGX83 are particularly suitable.

The ethylene unsaturated compound (B) is used in an amount of usually 5 to 50% by weight, preferably 20 to 30% by weight, based on the total amount of the prepolymer (A), of the compound (B).

The present invention also relates to a method of preparing the above radiation-curable composition, the method comprising: - a first step comprising reacting compounds (i), (iii) and (iv), optionally, and compound (ii), - a second step comprising reacting the product of the first step with the compound (v) such that a blocked (meth)acrylated polyurethane prepolymer is obtained; the end cap obtained after the second step (methyl) The acrylated polyurethane prepolymer is dispersed in an aqueous medium, and the optional step comprises: reacting with a neutralizing agent to convert the hydrophilic group provided by the compound (iii) into an anionic salt, - a step of selecting The chain extender (vii) reacts the (meth)acrylated polyurethane prepolymer obtained after the second step, an optional step comprising adding an ethylenically unsaturated compound (B).

If a chain extender (vii) is used, it is preferably added during or after the capping of the (meth)acrylated polyurethane prepolymer in an aqueous medium.

The addition of the ethylenically unsaturated compound (B) can be completed after the second step of the reaction. When the ethylenically unsaturated compound (B) is a compound which does not include a functional group reactive with an isocyanate group, the compound may be added before or during the second step of the reaction. According to a preferred embodiment of the invention, compound (B) is added to the reaction mixture together with compound (v).

According to another preferred embodiment of the present invention, a part of the compound (B) is added to the reaction mixture together with the compound (v), and the other part of the compound (B) is added to the reaction mixture after the second step. In this case, the same or different compound (B) can be used.

The non-ethylene unsaturated compound (C) may be added before, during or after the second step of the reaction, in addition to or instead of the compound (B). These compounds (C) are preferably selected from the group consisting of deuterated and/or hydroxylated polyacrylates such as Silclean. 3700. The amount of the compound (C) is usually from 0 to 30% by weight, preferably from 0 to 10% by weight, based on the total amount of the prepolymer (A) and optionally the compound (B), of the compound (C).

The composition and method according to the present invention are advantageous because they can provide a dispersion having a low volatile organic content (VOC), a high solid content, a low viscosity, a low particle size, an excellent stability, and a low film formation temperature. Since the "environmentally friendly" aspect of the product becomes an important added value in the market today, the elimination of solvents reduces the volatile organic content (VOC) and inhibits the amine from degrading the taste of the coated area and possible future health damage. Reduces the safety of skin and eye irritation enhancing products, and eliminates the need for special labels (Xi) to make the product more attractive to the user.

The aqueous dispersions of the present invention typically have a total solids content of from about 30 to 50% by weight, preferably from about 35 to 40% by weight; a viscosity of from 25 to 5,000 mPa.s, preferably from 25 to 200 mPa.s, at 25 ° C. 7 to 11, preferably a pH of from 7 to 8.5, an average particle size of from about 10 to 1000 nm, preferably from 50 to 150 nm. The film formation temperature is preferably from 0 to 20 ° C, more preferably from 0 to 5 ° C.

The composition according to the present invention can provide a coating which is not adhesive even before radiation hardening.

The radiation-hardening composition according to the present invention is preferably hardenable by ultraviolet irradiation, usually in the presence of a photoinitiator. It can also be hardened by electron beam irradiation using a composition without a photoinitiator. The composition according to the invention provides very rapid hardening.

The composition according to the present invention exhibits higher reactivity and can achieve higher linear velocity or lower irradiation energy hardening, and increase productivity.

The composition according to the present invention exhibits excellent chemical resistance against water, solvents and stains after radiation hardening, excellent mechanical resistance against scratches and abrasions - while still being fairly flexible at ambient or low temperatures Floor. These coatings also exhibit good adhesion to porous and non-porous substrates. Optical properties are related to good transparency and high gloss.

The coatings obtained from the compositions according to the invention result in selective mechanical properties (harder and softer) and polymer polarities (more hydrophilic or hydrophobic) covering a wide variety of different fields of application, for example for wood, plastics , glass, metal, and concrete coatings. The compositions according to the invention are also suitable for the manufacture of inks and varnishes. The invention therefore also relates to a method for making a composition of an ink, varnish or coating and a method of making an ink, varnish or coating using the above composition. The invention also relates to a method for preparing a coated article comprising the step of applying the article to a radiation-curable composition in accordance with the present invention.

The composition according to the invention is particularly suitable for the production of coatings for wooden furniture and plastic elastic flooring. The compositions according to the invention are also particularly suitable for coating plastic articles, in particular three-dimensional articles pre-coated with polyethylene, polypropylene, polycarbonate, optionally with other coatings such as polyurethane.

The composition according to the invention may therefore also contain different additives, such as biological agents, stabilizers, thickeners, coagulants, antifoams, wetting agents, waxes, and fillers.

The following examples describe the invention without limitation.

Example 1 :

A double-walled glass reactor equipped with a mechanical stirrer, a thermocouple, a vapor condenser, and a dropping funnel was charged with 45.3 g of a polyester polyol having an average molecular weight of 670 and a hydroxyl number of 167 mg KOH/g. Multi-condensation of neopentyl glycol with a mixture of adipic acid and isodecanoic acid in a weight ratio of 1:1, 109.2 g of an acrylic acid adduct (BPAAA) of biphenol A diglycidyl ether, 34.3 g of dimethylol Propionic acid (DMPA), 231.3 g of 1,1'-methylene fluorene (4-isocyanatocyclohexane) (H12MDI), 279 g of acetone, 3.1 g of TINUVIN 622, and 0.6 g of dibutyltin laurate, became a 10% acetone solution. The reaction mixture was heated with stirring until 60 ° C and kept under reflux until the isocyanic acid content reached a value of 1.09 meq / gram. Then, it was dissolved in 207.1 g of DTMPTA (which is a product including a mixture of di-trimethylolpropane triacrylate and di-trimethylolpropane tetraacrylate and having a hydroxyl number of 137 mg KOH/g). The methoxy phenol was slowly added to the reactor, and the reaction mixture was kept under reflux until the isocyanic acid content reached a value of 0.19 meq/gram. Then 209 grams of EBECRYL 1290 (hexafunctional aliphatic urethane acrylate) was added to the reaction mixture and stirred until a homogeneous mixture was obtained. The mixture was then cooled to 45 ° C and 25.8 grams of triethylamine was added with stirring. The resulting mixture was then slowly added to 1268 grams of water under high shear agitation at room temperature until a stable dispersion was obtained. The acetone was vacuum stripped at a temperature of 50 ° C until its content was less than 0.15% as measured by gas chromatography. The polymer dispersion is then cooled to below 30 ° C and 2.3 grams of biocide is added (Acticide) MBS). The dispersion was filtered through a 100 micron sieve and its solid content was adjusted to 40% by the addition of water. The dry content was measured by gravimetric analysis.

The viscosity of the dispersion was 33 mPa.s (measured by a Brookfield RVT viscometer using a N° 1 mandrel at 25 ° C at 50 rpm).

The average particle size of the aqueous polymer dispersion was 94 nm (measured by laser light scattering using a Malvern Autosizer Particle Analyzer).

The coarse sand content of the dispersion (i.e., the amount of residue of the polymer dispersion filtered in the 50 micron sieve) is less than 100 mg/liter.

The minimum film formation temperature (MFFT) measured by the dispersion on the gradient heating plate was 0 °C.

Colloidal stability was evaluated by observing decantation and/or phase separation on 200 grams of a sample placed in a 60 °C oven; it was more than 10 days before product degradation was observed. The properties of the dispersion are shown in Table 2 below.

Then with 1.5% photoinitiator (Additol BCPK) compounding the composition and using Additol VXW 6360: Water (1:1) up to 2% adjusts viscosity to approximately 1500 mPa.s (Brookfield) and evaluates reactivity, scratch resistance, stain resistance, hardness, flexibility, and adhesion as indicated below Sex.

Reactivity : This method covers the minimum UV dose required to completely crosslink a 36 micron coating wet coated onto a non-porous substrate (Silico Ultraflat). The coating was dried at 120 ° C for 1 minute and then hardened at 80 watts/cm UV lamp (Hg) at different conveyor speeds. The minimum dose is defined as the conveyor speed (m/min) where the solvent resistance is equal to or better than 50 acetone double rubs. The friction is carried out in a piece of cotton filled with acetone; one double rub is equal to the forward and backward stroke on the coated surface. The number of reports is the number of double rubs required to wear through the coating.

Scratch Resistance : This method covers the scratch resistance of a 36 micron coating wet coated onto a non-porous substrate (Silico Ultraflat). The coating was dried at 35 ° C for 10 minutes and then hardened 2 times at a speed of 5 meters per minute under a 80 watt / cm UV lamp (Hg). A piece of steel wool attached to an 800 gram hammer was used at room temperature and the scratched surface was evaluated by rubbing the coated surface back and forth. The number of reports is the number of single rubs that damage the surface and provide a visual loss of gloss due to wear.

Stain Resistance : This method covers the chemical resistance of a 36 micron coating wet coated onto a non-porous substrate (white, 5 mm thick PVC). The coating was dried at 120 ° C for 1 minute and then hardened at a speed of 5 m / min under a 80 W / cm UV lamp (Hg). The test substance was placed on the coating, covered with a microscope sheet and allowed to stand for 4 hours to assess resistance. The test substances used were tears, black polish, black alcohol pencil, BB750 colorant in water, SR380 colorant in volatile oil, and SG146 colorant in volatile oil. The stain was rubbed twice with a paper towel filled with isopropyl alcohol and washed. The residual stain was visually evaluated using a scale of 1-5, 5 = optimal. Its expected high value (5) provides the best protection against spillage of any household product.

Hardness : This method covers the surface hardness of a 120 micron coating wet coated to glass. The coating was dried at 40 ° C for 5 minutes, then dried at 80 ° C for 5 minutes, and finally hardened 3 times at a speed corresponding to the reactivity at 80 watts/cm UV lamp (Hg). The coated sample was allowed to stand in an air-conditioned room (20 ° C, humidity 50%) for 24 hours, and the pendulum hardness (Persoz) was determined at the surface 3. Calculate the average.

Pencil hardness : pencil hardness (ASTM D-3363). This method covers the hardness of a 36 micron coating wet coated onto a polycarbonate sheet. It is used in the industry to determine the scratch resistance of coatings. The coating was dried at 40 ° C for 10 minutes and hardened 2 times at a speed of 5 meters per minute under a UV lamp (Hg) of 80 watts / cm. The coated sample was allowed to stand in an air-conditioned room (20 ° C, humidity 50%) for a period of 24 hours. The pencil hardness is determined by using a pencil with a specific force and scratching the surface of the coating at a specific angle. The hardness was evaluated from soft to hard by grade 2B-B-HB-F-H-2H-3H-4H-5H-6H. It is desirable to have a high degree of hardness to provide optimum mechanical protection from the coating.

The flexible: This method covers the flexible coating 36 micron wet coating to a non-porous substrate (white, 5 mm thick PVC) of. The coating was dried at 120 ° C for 1 minute and then hardened at 5 m / min under a UV lamp (Hg) of 80 watts / cm. The flexibility of the coated PVC can be assessed after folding at 90° and then 180° at room temperature. Defects (cracks, adhesion loss) were recorded at 1-5, 5=best. The property is 1=90° severe defect; 2=90° moderate defect; 3=180° severe defect; 4=180° moderate defect; 5=180° without defect. The expected high value (5) does not cause problems when using a flexible substrate, and is a necessary condition for good temperature and dimensional stability on a hard substrate.

Water spot : This method covers the water resistance of a 36 micron coating wet coated onto a non-porous substrate (white, 5 mm thick PVC). The coating was dried at 120 ° C for 1 minute and then hardened at 5 m / min under a UV lamp (Hg) of 80 watts / cm. Resistance was assessed by cross-cutting the coated surface with a blade and placing a drop of water at room temperature for a period of one hour. Use a dry tissue to remove water. Surface degradation of whitening or degradation was visually assessed using grades 1-5, 5 = optimal. Its expected high value (5) provides the best protection against water spills.

Adhesion : This method covers the adhesion of a 36 micron coating wet coated to a non-porous substrate (white, 5 mm thick PVC). The coating was dried at 120 ° C for 1 minute and then hardened at 5 m / min under a UV lamp (Hg) of 80 watts / cm. The blade was used to complete 5 to 1 cm in the coating and the incision was ~1 mm apart, and then 5 in the lateral direction. Adhesion was measured using a tape that was firmly pressed against the cross-cut coating and quickly removed; the cross-cut surface area damage of the coating due to adhesion loss was expressed in 1-5 steps, 5 = optimal. High adhesion (5) is necessary to ensure a strong permanent connection between the coating and the substrate.

The results obtained are shown in Table 3 below.

Examples 2 to 5, 7 to 16, and Comparative Example 6R :

The procedure described in Example 1 was repeated in Examples 2 through 5, 7 through 16, except that the different amounts and different compositions specified in Table 1 below were used. The amounts of the different compounds are expressed in grams unless otherwise indicated.

The hexafunctional urethane EB was omitted in Examples 2 to 5, 6R, and 7 to 16. 1290.

In Example 4, DPHA (a mixture of diisopentyl alcohol hydroxypentaacrylate and diisopentaerythritol hexaacrylate having a hydroxyl number of 67 mg KOH/g) was used instead of DTMPTA.

In Example 5, DPHA (a mixture of diisopentyl alcohol hydroxypentaacrylate and diisopentyl alcohol hexaacrylate having a hydroxyl number of 67 mg KOH/g) was used instead of DTMPTA and DPHA was also used instead of EB. 1290.

Compound (iv) was not used in Comparative Example 6R: the acrylic acid adduct of biphenol A diglycidyl ether (BPAAA) was substituted with 15.4 g of ethylene glycol.

In Example 7, PCDL T4691 (Asahi Kasei), a butanediol: hexanediol (9:1) polycarbonate (having an average molecular weight of 1000 and having an average number of hydroxyl groups of 110 mg KOH/g) was used instead of the polyester diol. .

In Example 8, dimethylolpropionic acid (DMPA) was substituted with dimethylolbutanoic acid (DMBA). Neutralization is carried out stoichiometrically according to the molar number of carboxylic acid.

In Example 9, the polyester diol was stoichiometrically substituted with an excess of bisphenol A diglycidyl ether (BPAAA) acrylic acid adduct.

In Example 10 the polyester polyol was substituted with 2-ethyl-2-butyl-1,3-propanediol.

Polyester polyol in PRIPOL in Example 11 2033 (Unichema) is stoichiometrically substituted, which is a fatty acid dimer diol composed of 36 carbon atoms and having an average molecular weight of ~600 Daltons and a hydroxyl value of 196-206 mg KOH/g.

In Example 12, the diisocyanate (H12MDI) was 199 grams of H12MDI with 15.4 grams of DESMODUR. A mixture of N3300 (HDI isomeric cyanurate) was substituted with a molar ratio of 95:5.

Neutralization was accomplished in Example 13 with 32.1 grams of ammonia (110 mole % compared to the carboxylic acid) in the prepolymer in place of triethylamine (100 mole % compared to the carboxylic acid) in the aqueous phase.

In Example 14, 24.8 grams of IRR 154 (which is a polyoxygenated oil as the primary urethane acrylate) was added in an amount of 5% by weight based on the total weight of the prepolymer in place of EBECRYL. 1290.

In Example 15, ADDITOL was added in an amount of 0.1% to 0.1% by weight based on the total weight of the prepolymer. HGX83 (which is a fluorinated acrylate) instead of EBECRYL 1290.

In Example 16, 6.01 grams of SILCLEAN was added at a level of 7% based on the total weight of the prepolymer. 3700 (which is a polyoxymethylene modified hydroxy-functional acrylate having an average molecular weight of 15,000 Daltons, supplied as a 25% solution of methoxypropyl acetate) in place of EBECRYL 1290.

The properties of the composition are shown in Tables 2 and 3.

Comparative Examples 1 to 5 and 7 to 12 and Comparative Example 6R show better coating properties with the composition according to the present invention. In particular, Comparative Example 2 and Comparative Example 6R having exactly the same components as the compound (iv) showed the benefits of the composition according to the present invention.

Claims (12)

An aqueous radiation hardening type composition comprising - at least one (meth) acrylated polyurethane prepolymer (A) obtained from the following reaction: - at least one polyisocyanate compound (i), - Optionally, at least one polyol (ii), at least one containing at least one reactive group reactive with an isocyanate group, and allowing the polyurethane prepolymer to be reacted directly or in combination with a neutralizing agent a hydrophilic compound (iii) dispersed in an aqueous medium after salt, at least one (meth)acrylic compound (iv) containing at least two reactive groups reactive with an isocyanate group, at least one of which is intrinsically a (meth)acrylic compound (v) reactive with an isocyanate group selected from a poly(meth)acrylonitrile monohydroxy compound; and - optionally at least one ethylenically unsaturated compound (B), wherein the composition comprises a total amount of at least 3 meq (m) based on the total weight of (i), (ii), (iii), (iv), (v), and (B) The acrylated and optionally polymerizable ethylenically unsaturated groups. The radiation-hardening composition of claim 1 is obtained by a method comprising the following steps - a first step comprising reacting compounds (i), (iii) and (iv), optionally and compound (ii) ), - the second step, comprising reacting the product of the first step with the compound (v) A blocked (meth)acrylated polyurethane prepolymer is obtained; - the blocked (meth)acrylated polyurethane prepolymer obtained after the second step is dispersed in water In the medium, - a step comprising: reacting with a neutralizing agent to convert the hydrophilic group provided by the compound (iii) into an anionic salt, - a step of selecting a chain extender (vii) after the second step ( Methyl)acrylated polyurethane prepolymer, - optionally, an ethylenically unsaturated compound (B). The radiation-hardening composition of claim 1, wherein the polyisocyanate (i) is selected from the group consisting of aliphatic and cycloaliphatic polyisocyanates. The radiation-hardening composition of claim 1, wherein the polyol (ii) is a polyester polyol having a number average molecular weight of at least 400. The radiation hardening type composition of claim 1, wherein the hydrophilic compound (iii) is selected from the group consisting of hydroxycarboxylic acids represented by the formula (HO) _x R(COOH) _y wherein R represents 1 to 12 carbon atoms A straight or branched hydrocarbon residue, and x and y are independently an integer from 1 to 3. The radiation hardening type composition of claim 1, wherein the (meth)acrylic compound (iv) is selected from the reaction product of a diepoxypropyl compound and (meth)acrylic acid. The radiation hardening type composition of claim 6, wherein the (meth)acrylic compound (iv) is a diacrylate of bisphenol A diglycidyl ether. The radiation hardening type composition of claim 1, wherein the (meth)acrylic compound (v) is selected from the group consisting of aliphatic and/or aromatic polyols and (methyl) An esterification product of acrylic acid having a residual average hydroxyl functional group of about 1. The radiation hardening type composition of claim 1, wherein the (meth) acrylated polyurethane prepolymer (A) contains a total amount of (meth) acrylate groups according to the compound (i) The total weight in grams of (ii), (iii), (iv), and (v) is at least 3.0 meq. The radiation-hardening composition of claim 1, which comprises an ethylenically unsaturated compound (B) selected from the group consisting of esterification products of (meth)acrylic acid with a tri-, tetra-, penta-, or hexahydroxy polyol and mixtures thereof. . A method of preparing a radiation-curable composition according to any one of claims 1 to 10, which comprises: - a first step comprising reacting compounds (i), (iii) and (iv), and optionally Containing compound (ii), - a second step comprising reacting the product of the first step with compound (v) such that a blocked (meth)acrylated polyurethane prepolymer is obtained; - in a second step The blocked (meth)acrylated polyurethane prepolymer obtained afterwards is dispersed in an aqueous medium, and the optional step comprises reacting with a neutralizing agent to convert the hydrophilic group provided by the compound (iii) into a hydrophilic group. An anion salt, - an optional step in which a (meth)acrylated polyurethane prepolymer obtained after the second step is reacted with a chain extender (vii), an optional step comprising the addition of an ethylenically unsaturated compound ( B). A method of preparing a coated article comprising the step of applying the article to a radiation-curable composition as in claim 1 of the patent application.